In traditional methods for performing coronary artery bypass surgery, a segment of a blood vessel harvested from another portion of the body is used as an autogenous graft to bypass effectively the stenosed portion of the coronary artery in order to restore adequate blood flow distal to the blockage. In such a procedure, the saphenous vein is harvested from the surgical patient's leg and subsequently used as the graft vessel. In a large number of cases, the wound created in the leg is slow to heal and the patient endures considerable pain and irritation. In addition, surgeons have learned that, in general, an artery rather than a vein serves as a better, long term bypass graft when anastomosed to the coronary artery. Therefore, some surgeons harvest the radial artery from the patient's arm to be used as the bypass graft, or use both the saphenous vein and radial artery for multiple bypass surgery.
Instead of or in combination with harvesting the saphenous vein or the radial artery, many surgeons now use one of the internal mammary arteries (IMA) descending within the thoracic cavity along each side of the sternum of the rib cage. The IMA is in close proximity to the heart and therefore it is not necessary to completely remove it from the patient. The side branches are hemostatically severed, the main trunk of the vessel is occluded with a clamp, and then the IMA is severed at a point just superior to the patient's diaphragm so that the IMA is mobilized without disconnecting it from its original blood supply. The freed end of the IMA is then anastomosed to a coronary artery, usually to the left anterior descending (LAD) coronary artery, just distal to the stenosis. This procedure requires significant access and visibility into the upper thoracic cavity for the surgeon. The surgeon must free the IMA from the "ceiling" or wall of the internal thoracic cavity, while at the same time being very careful not to puncture or otherwise traumatize the IMA. The side branches of the IMA must be located and transected, usually by using an electrosurgical device, with minimal blood loss.
The most commonly used method of access to the thoracic cavity for the mobilization of the IMA and the anastomosis of it to the LAD coronary artery is a median sternotomy. For this procedure, a longitudinal incision is made through the patient's sternum on the midline of the chest. Then a surgical retractor is used to spread and hold apart the left and right rib cages, creating an opening which is typically about four to six inches wide. The muscles and other tissues of the chest wall are significantly traumatized by this procedure, and the post-operative healing process for the rejoining of the split sternum is sometimes very slow. As a result, the patient endures significant pain and the recovery time is long. In some cases there are significant complications and occasionally follow-up surgical procedures are required.
In recent years, new methods of access into the thoracic cavity have been developed in order to perform some of the surgical procedures done before through a median sternotomy. One minimally invasive method is called a mini-thoracotomy and involves access through an incision running intercostally (between two ribs) of the left chest wall. A surgical retractor again is used as for the median sternotomy, but in this case, the superior and inferior rib cages of the left chest are spread apart about two inches, thus resulting in much less overall trauma to the bones, muscles, and other tissues in the chest. Subsequently, the patient endures less pain and irritation following the surgery, and the recovery time is significantly decreased.
The mini-thoracotomy method of access to the thoracic cavity, however, has propagated the need for new surgical tools and methods because the opening into the thoracic cavity is considerably smaller than for the sternotomy. Also, since the IMA is attached to the thoracic cavity wall, the angle of approach the surgeon must use through the opening is very difficult since the inferior rib cage tends to obstruct the manipulation of surgical devices used for the procedure.
Many different surgical retractors are commercially available and are being used in thoracic surgery. There is a need for an apparatus and method that is adaptable for use with many of these surgical retractors, for the improvement of the visibility and access to the thoracic cavity. More specifically, there is a need for an apparatus to lift one side of a thoracotomic incision above the opposite side of the incision, and to do so in combination with the surgical retractor. Furthermore, there is a need for such an apparatus and method to be easy and quick to set-up since it is very important to minimize the length of time of the surgical procedure. Also, considering the high cost of surgical procedures today, it is important that such an apparatus be easy to clean and sterilize for reuse, or that it be low cost and disposable.
The apparatus also must accommodate variations in the human anatomy, specifically it should be adaptable to the curvature of the chest of the surgical patient, to the placement of the surgical incision, and to the orientation of the surgical retractor it is used with. There is a need for the apparatus to be stable during the surgical procedure, to maintain the lifting/retracting orientation desired by the surgeon, and to be as atraumatic as practical to the surgical patient. If a portion of the apparatus is to rest directly on the patient, and especially if that portion is supporting a force in order to achieve the desired function, there is a need to cover that portion with a resilient interface, so as to prevent bruising of the tissues in contact. Furthermore, once such an apparatus is set up during the surgical procedure, it is important that any portion of the apparatus in contact with the patient not slip or shift. This may disrupt a delicate step in the procedure and may cause injury to the patient.
There is a surgical need for such an apparatus which can be attached to any of numerous surgical retractors in use today, which can provide another means for support or attachment of other surgical devices used in the procedure. Often the surgeon wishes to hold or stabilize an organ or tissues within the cavity, and attach or support an ancillary holding tool on a fixed structure so that an assistant does not have to maintain the position of the holding tool throughout the procedure. Yet the surgical retractor arms may be too far away from the organ or tissue of interest to be used as a platform. What is needed is a bar or bridge that can attach to the arms of the surgical retractor and cross over the opening nearer to the organ or tissue of interest. Then this bridge can be used as a platform for supporting or attaching the ancillary holding device.